Objective To investigate the effects of simulated microgravity by rotary cell culture system (RCCS) on expression profiles of miRNA in mouse fibroblasts L929 cell line.Methods L929 cells were cultured in vitro and divided into simulated microgravity (SMG) group and normal gravity (NG) group according to the simple random method.Samples of two groups were collected on 7th day of culture and the total RNAs were extracted,labeled,and hybridized in sequence.Feature Extraction Software was used to collect the array images and get raw data,which were analyzed by Genespring Software.Differentially expressed miRNAs were identified and then validated by qRT-PCR.Target genes of differentially expressed miRNAs were predicted by the databases of Targetscan and microRNAorg,and the intersections of databases were identified as potential regulatory target genes.Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) analysis were applied to determine the roles of these target genes.Relevant biological functions and/or signaling pathways of the regulated genes especially related with wound healing process were categorized based on their enrichments.Then integration predictions of the miRNA and mRNA expression profiles had been proposed to refine the functional miRNA-mRNA relationships.The miRNA-mRNA functional network and miRNA-mRNA control network were constructed.Results Four miRNA genes were up-regulated significantly including mmumiR-669j,-122-5p,-30a-3p,-6516-3p,among which mmu-miR-669j was up-regulated at 52.84 folds with the greatest significance (P ＜ 0.05).Seventeen miRNA genes were down-regulated significantly including mmu-miR-21a-3p,-miR-28a-5p,-218-5p,-210-3p,-miR-19a-3p,-miR-31-3p,and-miR-19b-3p,among which mmu-miR-28a-5p was down-regulated at 15.47 folds with the greatest significance (P ＜ 0.05).The qRT-PCR showed a high concordance with the microarray results (P ＜ 0.05).Target gene prediction and functional enrichment analysis suggested that a variety of biological processes and signaling pathways involved in wound repair were significantly enriched (P ＜ 0.05).Function network and regulation network of miRNA-mRNA covered all the differentially expressed miRNAs,which suggested that miR-21 a-3p and predicted target gene Smad3 might play an important role in wound healing under microgravity.Conclusions Simulated microgravity by RCCS can significantly affect the expression of stress-related miRNAs in mouse fibroblasts L929.The miRNA target gene prediction and functional enrichment analysis based on gene chip technology may provide theoretical basis for illustrating the mechanism and management of weightlessness stress injury.

Objective:To investigate the clinical effect of arthroscopic debridement combined with high lateral tibial osteotomy and Giebel plate internal fixation in the treatment of varus knee osteoarthritis.Methods:From January 2016 to June 2018, 78 patients (96 knees) with varus knee osteoarthritis in Beijing Delcony Orthopedic hospital were treated by arthroscopic debridement combined with closed lateral tibial osteotomy and Giebel plate internal fixation. The femoral tibial angle (FTA) and hospital for special surgery knee score (HSS) score of knee joint were compared before and after operation.Results:70 patients (86 knees) were followed up for 12 to 28 months, with an average of 22.4 months. Bone healing was achieved at the osteotomy site 8 to 14 weeks after operation. Pain symptoms were relieved or disappeared significantly. The force line of X-ray examination was maintained at the postoperative level. The average knee femoral tibial angle was 187.6°preoperatively and 172.5° postoperatively, which showed significant statistical difference ( P<0.05). HSS knee score criteria: excellent: 70 knees; good: 10 knees; medium: 4 knees; poor: 2 knees. The excellent and good rate was 93.0%. The HSS score increased from (69.0±3.6) before operation to (87.2±8.1) after operation, with significant difference ( P<0.05). Conclusions:Arthroscopic debridement combined with high lateral tibial osteotomy and Giebel plate internal fixation is a very good method for the treatment of varus knee osteoarthritis, which is worthy of further clinical application.

Objective To explore the predictive value of systemic immune inflammatory index(SII),systemic inflammatory response index(SIRI),neutrophil to lymphocyte ratio(NLR),lymphocyte to monocyte ratio(LMR),platelet to lymphocyte radio(PLR),albumin to globulin(AGR)and heat shock protein 90α(HSP90α)in Fuhrman grade of clear cell renal cell carcinoma(ccRCC).Methods From October 2019 to August 2022,212 patients who underwent surgical treatment for ccRCC were divided into low-grade tumor group and high-grade tumor group according to Fuhrman grade.The independent influencing factors of Fuhrman grading were determined by univariate and multivariate Logistic regression analysis,and the predictive value of each inflammatory index to Fuhrman grading was evaluated by drawing Receiver operating characteristic curve(ROC).We constructed the line chart prediction model and evaluated the effectiveness of the model.Results The preoperative levels of SII,PLR,AGR,HSP90α and the maximum diameter of tumor were significantly different between high-grade group and low-grade group(P＜0.05).Logistic regression analysis showed that the maximum diameter of tumor,PLR,AGR and HSP90α were independent influencing factors of Furhman grade.By drawing the ROC curve,it was found that the area under the curve(AUC)of PLR,AGR and HSP90α to predict Furhman grade were 0.641,0.675 and 0.696.In addition,the Furhman grade line chart prediction model had good prediction ability,the AUC was 0.789(95％CI:0.717～0.862),the sensitivity was 61.80％,and the specificity was 85.40％.Conclusions There was a significant correlation between inflammation-related indexes in peripheral blood and Furhman grade of clear cell renal cell carcinoma.The Furhman grade line chart prediction model based on the maximum diameter of tumor and peripheral blood inflammation index has good predictive ability.

Objective To explore the value of T2*mapping in quantitatively evaluate changes in knee joint cartilage and subchon-dral bone of new recruits before and after intensive training.Methods MRI scans of the right knee joint were performed three times on 20 new recruits:before intensive training,after one week of intensive training,and after one month of rest.The knee joint cartilage was divided into six regions:lateral femur(LF),medial femur(MF),lateral tibia(LT),medial tibia(MT),patella cartilage(PC),and trochlea cartilage(TC).Using the posterior angle of the meniscus as a boundary,LF and MF were divided into the cLF/cMF and pLF/pMF.Divid-ed into superficial zone(SZ)cartilage and deep zone(DZ)cartilage based on a thickness of 1/2 of the cartilage.The subchondral bone was divided into superficial bone(SB)within 5 mm of the joint cartilage,and deep bone(DB)within 6-10 mm of the joint cartilage.The T2*values of each region of cartilage and subchondral bone were evaluated through region of interest(ROI)analysis.Single fac-tor analysis of variance was used to compare the changes in T2*values.The LSD test method was used for inter-group comparison.Results After one week of intensive training,MT-SZ,cMF-SZ,PC-SZ,TC-SZ were significantly higher than before intensive training(P＜0.05).After one month of rest,there was no statistically significant difference in the T2*value of the cartilage area compared with before intensive training(P＞0.05).There was a trend of"rising first and then falling".There was no statistically signifi-cant difference in the T2*value of subchondral bone of the knee joint before intensive training and after one week of intensive training(P＞0.05).Compared with after one month of rest,except for cLF-DB,pLF-DB,trochlea cartilage-deep bone(TC-DB),the T2*value of the subchondral bone of the remaining knee joint increased before intensive training and after one week of intensive training,with sta-tistically significant differences(P＜0.05).Conclusion T2*mapping can display the changes in the ultrastructure and biochemical components of joint cartilage and subchondral bone after the new recruits intensive training,detect early injuries and conduct non-invasive quantitative evaluation.

Objective To explore the value of MR diffusion tensor imaging(DTI)in evaluating the effect of march training on the thigh muscles of recruits.Methods DTI scans of the right thigh were performed three times in forty recruits:before and after the march training and one month after the rest.Fractional anisotropy(FA)was measured on the cross-sectional images of the thigh muscles,including rectus femoris(RF),vastus medialis(VM),vastus lateralis(VL),vastus intermedius(VI),gracilis muscle(GM),sartorius muscle(SM),semitendinosus muscle(STM),semimembranosus muscle(SMM),long head of biceps femoris(LHBF)and short head of biceps femoris(SHBF).The percentage changes in FA values of each muscle after the training and rest were calculated.Paired samplet-tests were used to analyze the differences in FA among the thigh muscles at different time points,and one-way ANOVA was used to analyze the differences in the percentage changes of FA among the thigh muscles after the training and rest.Results Compared to pre-training,the FA values of all thigh muscles significantly decreased after the training,with statistical differences(P＜0.05).After the rest,the FA values of all thigh muscles recovered,but statistical differences remained in RF(P＜0.001),VM(P＜0.001),VL(P=0.001),STM(P=0.046),and LHBF(P=0.013).After the training and rest,the FA values of the recruits'thigh muscles showed a"decreasing first and then increasing"trend.There were statistical differences in the percentage changes of FA after the training and the recovery percentages of FA after the rest among the thigh muscles(P＜0.001,P＜0.001).Conclusion DTI may reflect the ultra-structure changes in the thigh muscles of recruits after the march training and provide a quantitative and noninvasive assessment of muscle micro-injuries.